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Biomedical subjects

J Amara

Publications and source records attributed to J Amara.

5 recordsLinked to original sources

Human basophil degranulation triggered by very dilute antiserum against IgE.

When human polymorphonuclear basophils, a type of white blood cell with antibodies of the immunoglobulin E (IgE) type on its surface, are exposed to anti-IgE antibodies, they release histamine from their intracellular granules and change their staining properties. The latter can be demonstrated at dilutions of anti-IgE that range from 1 x 10(2) to 1 x 10(120); over that range, there are successive peaks of degranulation from 40 to 60% of the basophils, despite the calculated absence of any anti-IgE molecules at the highest dilutions. Since dilutions need to be accompanied by vigorous shaking for the effects to be observed, transmission of the biological information could be related to the molecular organization of water.

Antibodies, Anti-Idiotypic↗

Mandibular pain as the initial and sole clinical manifestation of coronary insufficiency: report of case.

A case of anginal pain limited to the mandible with secondary radiation of the pain to the neck and clavicular regions is presented. Although the pain was initially diagnosed as odontogenic in origin, further historical workup suggested the suspicion of referred pain from coronary insufficiency. Immediate cardiac evaluation confirmed the nature of the pain as angina. Important aspects involved with differential diagnosis of referred anginal pain are also discussed.

Aged↗

Tamoxifen and 5-fluorouracil in breast cancer: cytotoxic synergism in vitro.

The cytokinetic and cytotoxic interactions involved in combining tamoxifen, methotrexate, and 5-fluorouracil were studied in two hormone-dependent human breast cancer cell lines, 47-DN and MCF-7. These cells had measurable cytosol and nuclear estrogen receptor and cytosol progesterone receptor. Growth of the MCF-7 cells in medium containing gelding serum was stimulated maximally by addition of 10 pM estradiol. Both MCF-7 and 47-DN cells showed dose-dependent in vitro growth inhibition on exposure to tamoxifen, and toxicity from tamoxifen at concentrations up to 10 microM could be prevented by 1 nM estradiol. After exposure of 47-DN cells to 10 microM tamoxifen, cytosol progesterone and nuclear estrogen receptor levels were still detectable at 30 and 60% of control values. With this same concentration of tamoxifen, 47-DN cells in S phase declined 50% in association with a buildup of G0-1 cells. By clonogenic assay, tamoxifen enhanced 47-DN and MCF-7 cytotoxicity to 5-fluorouracil and 5-fluorouridine, but not to methotrexate alone. When given either concurrently or using a pretreatment-synchronizing schedule, tamoxifen enhanced markedly the growth inhibition of sequentially combined methotrexate and 5-fluorouracil. Isobologram analysis was used to prove that the cytotoxic interaction between tamoxifen and 5-fluorouracil was synergistic.

Breast Neoplasms↗

Cross-sectional clinical evaluation of recurrent enamel caries, restoration of marginal integrity, and oral hygiene status.

Both marginal quality and oral hygiene status have strong effects on the risk of recurrent caries. Although there was no statistically significant interaction between these two parameters in this study, the influence of each variable was dependent on its severity. There is a difference between the behavior or the likelihood of recurrent caries on occlusal surfaces as compared with smooth surfaces. On the smooth surfaces, there is a continued increased risk with decreasing marginal quality; the occlusal surfaces, however, show no change in vulnerability beyond a modified marginal quality score of 3. Variation in oral hygiene had a more pronounced effect on the probability of recurrent caries of restorations with moderate margin scores than it did on restorations with either very poor or very good cavosurface margins. This work further emphasizes the importance of technically good restorative care at the operative visit, which, coupled with conscientious oral hygiene, should have a positive effect on increasing the longevity of restorations and decreasing the need for replacement.

Adolescent↗